It is well-known among prosthesis wearers that walking in downhill slopes is problematic. If the prosthesis wearer does not have the possibility to adjust the foot angle only the heel will contact the ground when walking in a steep downhill. If the foot angle exceeds a certain degree it will due to the absence of certain muscle groups be difficult to resist the knee from collapsing. Therefor the prosthesis wearer often chooses to walk sideways downhill.
Prosthesis wearers that do not have a height adjustable foot have problems changing to a shoe with another heel height, and to quickly choose to walk without shoes. Individual adaption of the foot in height also reduces the problem of back pain and worn out hip-joints.
In order to reduce the above problem prostheses with adjustable angular position between the foot and the leg prosthesis have been developed. It is for example known through SE 511 750 a device in a leg prosthesis provided with a foot which via a pivot axle is connected to a leg prosthesis and in which the angular position between the leg prosthesis and the foot is adjustable. For increasing the usefulness for prostheses for users whose amputation site is located just above the foot it is necessary that the prosthesis including adjustment mechanisms have a compact design. In SE 511 750 this is provided by designing the adjustment mechanism in the form of a curved cylinder and curved piston parts located therein. The complicated geometry make this type of prosthesis expensive and complicated to manufacture.